Flexible mask coupling

ABSTRACT

Mask interfaces having mask frames and mask seals are disclosed. Headgear and breathing conduits can be connected to the mask interfaces. The connection between the mask seals and the mask frames can enable movement of the mask seals relative to the mask frames. The relative movement may be at the mounting locations of the mask seals and mask frames.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure generally relates to connections between maskframes and mask seals. More particularly, the present disclosure relatesto such connections that facilitate relative movement between the maskframes and mask seals.

2. Description of the Related Art

The treatment of obstructive sleep apnea (OSA) by continuous positiveairway pressure (CPAP) flow generator systems involves the continuousdelivery of pressurized air to the airways of a human via a conduit andan interface (e.g., a mask). Typically, the interface creates at least asubstantial “seal” on or around the nose and/or the mouth. This act ofcreating a “seal” results in pressurization of the patient's airway andthe CPAP system.

Due to the simple physics of pressurising this mask, it results in aforce being generated that is proportional to the projected area of themask and the pressure difference between the inside and the outside ofthe mask. For the mask to be stable on the patient's face, this forcemust be opposed by an equal and opposite force. A head gear system istypically used to provide the equal and opposite force.

In addition to this direct force created by the pressurization of themask, there are a number of external forces that the head gear alsocounteracts. Examples of other external forces includes pull or drag onthe delivery tube and loading induced by the patient/bedding on the maskas the patent moves.

SUMMARY OF THE DISCLOSURE

These external forces typically are considerably larger (e.g., about 3-5times larger) than the force required to restrain the mask against thepressure-based movement. The implications that this has on traditionalmask and headgear system is that changes to the external forcestypically result in movement of the mask system until the headgearsystem is able to counteract these forces.

The movement of the mask system results in loading change and/ormovement of the seal, either of which can change how the seal interactswith the patient's skin. This change may be in the pressure level theseal exerts on the patient's skin or, in some cases, it is sufficient toenable a leak to be created between the seal and the patient's skin.

The effect of these changes on the patient is that the patient interactswith the mask system to reposition it on their face, in either asub-conscious manner or a conscious manner, in order to correct the fit,which may be defined as an “equipment induced” sleep interruption.Equipment induced sleep interruption compromises the therapy that thepatient is receiving.

The creation of practical and not so practical solutions to theunderlying causes of equipment induced sleep interruption has been thesubject of considerable development effort from numerous organizations,which has resulted in numerous patents.

The following is a description of a number of practical options toimprove current designs by providing a decoupling mechanism between themask seal member and the mask frame to minimise the effect on the sealof external forces exerted on the mask frame and/or small movement ofthe mask frame. In effect, certain features, aspects and advantages ofvarious embodiments of the present disclosure provide a “suspension”mechanism between the seal and the mask frame.

An object of the present disclosure is to provide an interface that willat least provide the industry and users with useful choice.

In accordance with at least one of the embodiments disclosed herein, apatient interface is provided comprising a seal portion sized and shapedto surround the nose and/or mouth of a user and adapted to create atleast a substantial seal with the user's face, a frame portion adaptedto couple to the seal portion, a connector that permits the interface tobe coupled to a conduit; and a coupling that permits the seal portion tomove relative to the frame portion.

In some configurations, the relative movement of the seal portion isgenerally constrained to a slip plane across the frame portion of theinterface. The relative movement can be permitted generally acrossand/or perpendicular to the slip plane.

In some configurations, the relative movement of the seal portion isconstrained to a spherical boundary. The coupling can be a ball andsocket type joint. The relative movement can be permitted around acommon rotational center. In some configurations, the relative movementcan be permitted along a principal axis of the ball and socket joint.The seal portion can comprise a socket and the frame portion cancomprise a complementary ball.

In some configurations, the relative movement of the seal portion isconstrained to a cylindrical boundary. The coupling can be a shaft andbearing type joint. The relative movement can be permitted along an axisof the cylindrical boundary.

In some configurations, the patient interface can comprise anycombination of the relative movements described above.

In accordance with at least one of the embodiments disclosed herein, apatient interface is provided comprising a seal portion sized and shapedto surround the nose and/or mouth of a user and adapted to create atleast a substantial seal with the user's face, the seal portioncomprising a seal inlet; a frame portion comprising a frame inlet and aframe outlet, the frame portion adapted to couple to the seal portion; aconnector comprising a first end adapted to couple with the frame inletand a second end that permits the interface to be coupled to a conduit;and a coupling adapted to couple the frame outlet and the seal inlet,and permit the seal portion to move relative to the frame portion;wherein the coupling is generally the same size and generally alignedwith the frame inlet.

In some configurations, the relative movement of the seal portion isgenerally constrained to a slip plane across the frame portion of theinterface. The relative movement can be permitted generally acrossand/or perpendicular to the slip plane.

In some configurations, the coupling is made of a flexible material. Thecoupling can have a bellows construction.

The term “comprising” as used in the specification and claims means“consisting at least in part of’. When interpreting a statement in thisspecification and claims that includes “comprising,” features other thanthat or those prefaced by the term may also be present. Related terms,such as “comprise” and “comprises,” are to be interpreted in the samemanner.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the disclosure. Unless specificallystated otherwise, reference to such external documents is not to beconstrued as an admission that such documents, or such sources ofinformation, in any jurisdiction, are prior art, or form part of thecommon general knowledge in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentdisclosure will now be described with reference to the drawings of oneor more preferred embodiments, which embodiments are intended toillustrate and not to limit the disclosure, and in which figures:

FIG. 1 shows the design of a typical mask.

FIG. 2 shows a cross section through a mask with a flexible couplingbetween the mask seal and the mask frame.

FIG. 3 shows a cross section through a mask with a ball and socket stylecoupling between the mask seal and the mask frame.

FIG. 4 shows a nasal mask and associated force vectors.

FIG. 5A shows the force vectors for a mask with no external forces.

FIG. 5B shows the force vectors for a mask with external forces.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

The application of pressure to the inside of a mask results in a forcevector being created which can be restrained by an equal and oppositeforce, as discussed above. FIG. 4 shows an example of such aconfiguration using a side view of a nasal mask wearer. The pressureforce vector F_(P) that results is a combination of the pressuredifference between the inside and the outside of the mask seal, theprojected area of the mask seal and the orientation of the mask. Overthe combination of pressures potentially used for CPAP (about 4-20 cmwater), for a typical nasal mask, this force varies between at leastabout 0.7N and less than or equal to about 3.5N. FIG. 5A illustrates theforce vectors for situations with no external forces. As shown in thefigure, the pressure force F_(P) is restrained by an equal and oppositeretention force F_(R), which can be provided by headgear or otherretention system.

FIG. 4 also shows an external force F_(E) that can be exerted on themask, such as by pulling forces from an attached hose or other externalforces. FIG. 5B illustrates the force vectors for situations thatinclude external forces F_(E). As shown in FIG. 5B, the combination ofthe pressure force F_(P) and the external force F_(E) can have a totalforce F_(T). The total force F_(T) is restrained by an equal andopposite retention force F_(R), which can be provided by headgear orother retention system.

The external forces F_(E) that may be applied to a mask system,primarily from hose drag, typically result in mask retention forcesF_(R) being about 3-5 times greater than what is required to purely holdthe mask in place (e.g., at least about 10.5N to less than or equal to17.5N). The vector that these external forces F_(E) pass though variesdue to the nature of how they are created and, to resolve them, a smallamount of head gear stretch or slip may occur.

Because the force that opposes hose pull is considerably larger than theminimum force required to hold the seal in place, the hose pull-basedforce dominates and, when a conventional mask is in use, the hosepull-based force results in seal movement on the patients face, whichtypically creates a leak or compromises therapy.

With reference to FIG. 1, a mask interface 100 generally comprises amask seal 110, which is configured to be positioned on the skin of apatient, and a frame 120, to which the mask seal is mounted. The maskframe 120 can include attachment points 140 for headgear or otherwise beconfigured to connect to headgear. A conduit can be connected to one ormore of the mask frame and the mask seal. In some configurations, theconnection to the mask frame and/or mask seal is a rotating connector orswiveling connector. In the illustrated configuration, the conduit canbe connected to a ball jointed elbow 130 and the ball jointed elbow isconnected to the mask frame 120.

The disclosed mask assemblies seek to decouple or segregate the maskseal from the mask frame that carries/supports the tube connection.There are a number of embodiments to achieve the segregation. Withreference to FIGS. 2-3, some embodiments of a mask interface inaccordance with the present disclosure are illustrated.

In some configurations, such as the interface 200 shown in FIG. 2, themask seal 210 includes a seal inlet 212 and the mask frame 220 includesa frame outlet 222. In the illustrated configuration, the seal inlet 212and the frame outlet 222 are shown as male connectors. The seal inlet212 and frame outlet 222 can be coupled by a coupling member 250, whichcan be flexible or otherwise allow relative movement between the maskseal 210 and mask frame 220. For example, the coupling member can atleast partially be made of rubbers, textiles, plastics, or othersuitable material and can be flexible and/or stretchable. In someconfigurations, the coupling member can be a slip coupling. In theillustrated configuration, the coupling member 250 comprises anarticulable member. The articulable member can have a bellowsconstruction with an undulating side wall.

With continued reference to FIG. 2, the interface 200 can have aconnector 230 for connection with a conduit that is in fluidcommunication with a gas delivery system. The connector 230 can beconfigured to be coupled with a frame inlet of the mask frame 220. Inthe illustrated configuration, the connector 230 and mask frame 220 havea ball and socket connection. In other configurations, other connectiontypes can be used, such as rotational couplings and fixed joints. Theframe outlet 222 and the seal inlet 212 can be generally aligned withthe frame inlet. The area of the opening of the seal inlet 212 and theframe outlet 222 can be approximately the same size as the opening ofthe frame inlet. This can allow the flow of gases to travel through theinterface without substantially impeding, restricting or reducing theflowrate of the gases flow. The coupling member 250 can also begenerally the same size and generally aligned with the frame inlet. Thisadvantageously helps improve the flexibility and relative movementbetween the seal portion and frame portion. For example, because thecoupling member is localized around the frame inlet, as opposed to alarger perimeter of the seal portion, the coupling member is more easilybendable and provides improved flexibility between the seal portion andthe frame portion. In some configurations, the coupling member 250 canhave non-uniform stiffness or structure to allow flexing in onedirection easier than others. For example, the bottom portion of thecoupling member can be softer than the top portion of the couplingmember such that the frame is biased to bend downward when the interfaceis on a patient. Furthermore, the coupling member can advantageouslyhelp reduce the probability of the seal moving or being displaced on theuser's face due to the frame being moved or pulled. The coupling membercan provide the ability for the frame to have relative and independentmovement from the seal.

Other configurations are possible. In some configurations, the couplingmember can be attached directly to the mask seal and mask frame withoutmale connector portions. The coupling member can be attached by any of avariety of suitable means, such as adhesives, welding, and the like. Insome configurations, the coupling member can be removably attached suchas with clips, hook and loop fasteners, straps, screws, and the like. Insome configurations, the coupling member can be integrated into one orboth of the mask frame and the mask seal. For example, the couplingmember can be overmoulded onto the mask seal at one end and attached tothe mask frame at the other end through any of the attachment meansdiscussed previously.

With reference to FIG. 3, in some configurations, the mask frame 320 ofthe interface 300 includes a frame inlet 324 that receives the first end332 of the elbow 330, and a frame outlet 326 that is received by a sealinlet 314 of the mask seal 310. In the illustrated configuration, theframe inlet 324 is a female connector portion and the first end 332 is aball joint. The illustrated configuration also shows the frame outlet326 as a male connector portion and the seal inlet 314 as a femaleconnector portion. In other configurations, the connections can bereversed, for example the frame outlet can be a female connector portionand the seal inlet can be a male connector portion. In someconfigurations, the seal inlet 314 of the mask seal 310 and the frameoutlet 326 of the mask frame 320 define a ball and socket configurationwith a common rotational center 328. Other configurations are possible,such as rotational bearings, coiled shafts and universal joints.

Advantageously, the two couplings shown in FIG. 2 and FIG. 3 can enableindependent movement between the frame and the seal which contacts thepatients face. In some configurations, the independent movement isrelative movement between the portion of the mask frame that is coupledto the mask seal and the portion of the mask seal that is coupled to themask frame. In other words, the relative movement is between the twomounting locations. In some configurations, the independent movementbetween the frame and the seal is a slip movement. In other words, theindependent movement is along a slip plane 260 defined across the maskframe of the interface, as illustrated in FIG. 2. The slip plane 260 canbe generally normal to a plane that extends in a generally verticaldirection and that substantially bisects the interface. In someconfigurations, the relative movement can include movement generallyperpendicular to the slip plane. In some configurations, the relativemovement is constrained to a generally spherical boundary with a commonrotational center, such as that created by a ball and socket type joint.In some configurations, the relative movement can be along the principalaxis of the ball and socket type joint (i.e., the axis of connection ofthe ball and socket). In some configurations, the relative movement isrotational and constrained to a generally cylindrical boundary, such asthat created by a shaft and bearing type joint. In some configurations,the relative movement can be permitted along an axis of the cylindricalboundary. In some configurations, any combination of these relativemovements can result. In some configurations, the ball and socket typejoint can be asymmetric to allow flexing in one direction easier thanothers, or decoupling in one direction easier than others.

Although the present disclosure has been described in terms of certainembodiments, other embodiments apparent to those of ordinary skill inthe art also are within the scope of this disclosure. Thus, variouschanges and modifications may be made without departing from the spiritand scope of the disclosure. For instance, various components may berepositioned as desired. Moreover, not all of the features, aspects andadvantages are necessarily required to practice the present disclosure.Accordingly, the scope of the present disclosure is intended to bedefined only by the claims that follow.

1. A patient interface, comprising: a seal portion sized and shaped tosurround the nose and/or mouth of a user and adapted to create at leasta substantial seal with the user's face, the seal portion comprising aseal inlet; a frame portion comprising a frame inlet and a frame outlet;a connector that permits the interface to be coupled to a conduit thatis in fluid communication with a gas delivery device, the connectorconfigured to be coupled with the frame inlet; and a coupling betweenthe seal inlet and the frame outlet to permits the seal portion to moverelative to the frame portion, wherein the coupling comprises a ball andsocket joint and/or a shaft and bearing joint. 2-3. (canceled)
 4. Thepatient interface of claim 1, wherein the relative movement of the sealportion is constrained to a spherical boundary.
 5. (canceled)
 6. Thepatient interface of claim 1, wherein relative movement is permittedalong a principal axis of the ball and socket joint.
 7. The patientinterface of claim 1, wherein the seal inlet comprises a socket and theframe outlet comprises a complementary ball of the ball and socketjoint, or the frame outlet comprises the socket and the seal inletcomprises the complementary ball.
 8. The patient interface of claim 1,wherein the relative movement of the seal portion is constrained to acylindrical boundary.
 9. (canceled)
 10. The patient interface of claim18, wherein relative movement is permitted along an axis of thecylindrical boundary.
 11. (canceled)
 12. A patient interface as claimedin claim 1, wherein the coupling is generally the same size andgenerally aligned with the frame inlet. 13-16. (canceled)
 17. A patientinterface as claimed in claim 1, wherein the frame outlet is a maleconnector portion and the seal inlet is a female connector portion, theframe outlet received in the seal inlet, or the frame outlet is a femaleconnector portion and the seal inlet is a male connector portion, theseal inlet received in the frame outlet.
 18. A patient interface asclaimed in claim 1, wherein the connector is an elbow, and a first endof the elbow is a ball and the frame inlet is a female connector portionadapted to receive the ball.
 19. A patient interface, comprising: a sealportion sized and shaped to surround the nose and/or mouth of a user andadapted to create at least a substantial seal with the user's face, theseal portion comprising a seal inlet; a frame portion comprising a frameinlet and a frame outlet; a connector that permits the interface to becoupled to a conduit that is in fluid communication with a gas deliverydevice, the connector configured to be coupled with the frame inlet; andwherein the frame outlet is a male connector portion and the seal inletis a female connector portion, the frame outlet received in the sealinlet, or wherein the frame outlet is a female connector portion and theseal inlet is a male connector portion, the seal inlet received in theframe outlet, to form a coupling that permits the seal portion to moverelative to the frame portion.
 20. A patient interface as claimed inclaim 19, wherein the seal inlet comprises a socket and the frame outletcomprises a complementary ball to form a ball and socket joint, or theframe outlet comprises the socket and the seal inlet comprises thecomplementary ball to form the ball or socket joint.
 21. A patientinterface as claimed in claim 20, wherein relative movement is permittedalong a principal axis of the ball and socket joint.
 22. The patientinterface of claim 19, wherein the relative movement of the seal portionis constrained to a spherical boundary.
 23. A patient interface asclaimed in claim 19, wherein the frame outlet and the seal inlet form ashaft and bearing joint.
 24. A patient interface as claimed in claim 19,wherein the connector is an elbow, and a first end of the elbow is aball and the frame inlet is a female connector portion adapted toreceive the ball.